function show_basis_c0(dof_map, V, T, idx, d, d_plot)

n_dof = max(max(dof_map));
x = zeros(n_dof,1);
x(idx) = 1;

[vtx, tri, u] = heval(dof_map, V, T, x, d, d_plot);

trisurf(tri, vtx(:,1), vtx(:,2), u);